Low density, high loft nonwoven substrates

ABSTRACT

The present invention relates to a nonwoven substrate suitable for use as a cleaning sheet having density of no more than 0.15 g/cm 3  and comprising at least one fibrous web, said substrate comprising at least one first region and at least one second region wherein said second region comprises protruding elements and is capable of greater geometric deformation than said first region. The present invention also relates to the use of said substrates as cleaning sheets, a process of cleaning soiled surfaces with said substrates and a method of making said substrates.

CROSS REFERENCE TO RELATED APPLICATIONS

[0001] This application claims the benefit of U.S. ProvisionalApplication No. 60/406,855 filed Aug. 29, 2002.

FIELD OF THE INVENTION

[0002] The present invention relates to nonwoven substrates, having lowdensity, preferably high loft and which comprise at least one fibrousweb, at least a first region and at least a second region wherein thesecond region comprises at least one protruding element and is capableof greater geometric deformation than the first region. The secondregion preferably comprises protruding rib-like and/or folding elementswithin or on the surface of the substrate. The present invention alsorelates to a process capable of producing substrates having thedescribed first and second regions and preferably protruding rib-likeand/or folding elements within or on the surface of the substrate.

[0003] The substrates of the present invention have a wide range ofpotential uses, but are particularly well suited for use as disposablesurface care products such as dry dusting sheets, wet and dry floorcleaning wipes/pads, wet and dry counter wipes, and the like.

BACKGROUND OF THE INVENTION

[0004] The use of nonwoven sheets for cleaning surfaces are known in theart. Such sheets typically utilize a composite of fibers where thefibers are bonded via adhesive, entangling or other forces. See, forexample, U.S. Pat. No. 3,629,047 and U.S. Pat. No. 5,144,729. To providea durable wiping sheet, reinforcement means have been combined with thestaple fibers in the form of a continuous filament or network structure.See, for example, U.S. Pat. No. 4,808,467, U.S. Pat. No. 3,494,821 andU.S. Pat. No. 4,144,370. Also, to provide a product capable ofwithstanding the rigors of the wiping process, prior nonwoven sheetshave employed strongly bonded fibers via one or more of the forcesmentioned above. While durable materials are obtained, such strongbonding may adversely impact the materials' ability to pick up andretain particulate dirt. In an effort to address this concern, U.S. Pat.No. 5,525,397 to Shizuno et al. describes a cleaning sheet comprising apolymeric network layer and at least one nonwoven layer, wherein the twolayers are lightly hydroentangled so as to provide a sheet having a lowentanglement coefficient. The resulting sheet is said to providestrength and durability, as well as improved dust collecting performancebecause the composite fibers are lightly hydroentangled. Sheets having alow entanglement coefficient (i.e., not more than 500 m) are said tooffer better cleaning performance because a greater degree of fibers areavailable for contact with dirt.

[0005] While the sheets described in the '397 patent are alleged toaddress some of the problems with prior nonwoven cleaning sheets, thosesheets appear to be generally uniform, at least on a macroscopic leveland are essentially of a uniform caliper, again on a macroscopic level.However a sheet having such uniformity is not particularly suitable forcollecting and entrapping soil of a diverse size, shape, etc.

[0006] As such, there is a continuing need to provide cleaning sheetsthat offer improved soil removal, collection and entrapment.Accordingly, it is an object of this invention to overcome the problemsof the prior art and particularly to provide a structure more capable ofremoving, collecting and entrapping various types of soil. Specifically,it is an object of the present invention to provide a nonwoven substratehaving significant three-dimensionality and thus provide a cleaningsheet exhibiting enhanced soil removal, collection and entrapment.

SUMMARY OF THE INVENTION

[0007] The present invention relates to a nonwoven substrate suitablefor use as a cleaning sheet having density of no more than 0.15 g/cm³and comprising at least one fibrous web, said substrate furthercomprising at least one first region and at least one second regionwherein said second region comprises protruding elements and is capableof greater geometric deformation than said first region.

[0008] In a preferred embodiment the present invention relates to anonwoven substrate wherein the second regions comprise protrudingrib-like structures and/or folding elements within or on the surface ofthe sheet.

[0009] The present invention also relates to a process of forming theabove substrate wherein the substrate is fed through a pair ofcorresponding rolls (502 and 504) at least one of said pair of rolls(502) comprising at least one, preferably a plurality of toothed (506)and grooved (508) regions about the circumference of the rolls, saidgrooved regions forming the first regions of the substrate and saidtoothed regions forming the second regions of the substrate.

BRIEF DESCRIPTION OF THE DIAGRAMS

[0010] While the specification concludes with claims particularlypointing out and distinctly claiming the present invention, it isbelieved that the present invention will be better understood from thefollowing description in conjunction with the accompanying drawings, inwhich like reference numerals identify like elements and wherein:

[0011]FIG. 1 is a simplified perspective view of a preferred apparatusused to form substrates of the present invention with a portion of theapparatus being tilted to expose the teeth.

[0012]FIG. 2 is a simplified side elevation view of a static press usedto form the substrate of the present invention.

[0013]FIG. 3 is a is a simplified side elevation view of a continuous,dynamic press used to form the substrates of the present invention.

[0014]FIG. 4. is a simplified illustration of another apparatus used toform the substrates of the present invention.

[0015]FIG. 4a. is a blown up illustration of the boxed area in FIG. 4,showing the distance of depth of engagement (DOE) of two correspondingrolls.

[0016]FIG. 5. is another simplified illustration of another apparatusused to form the substrates of the present invention.

[0017]FIG. 6. is a plan view illustration of a preferred embodiment ofthe substrate of the present invention showing the diamond shaped secondregions.

[0018]FIG. 7. is a plan view illustration of a preferred embodiment ofthe substrate of the present inventions showing two patterns of secondregions; diamond shaped and rows. The diamond shapes comprise foldingprotruding elements and are found toward the center of the substratewhereas the rows comprise rib-like protruding elements and are foundtoward the outer limits of the substrate.

[0019]FIG. 8. is a plan view illustration of a preferred embodiment ofthe substrate of the present inventions showing two patterns of secondregions; diamond shaped and rows. The diamond shapes comprise foldingprotruding elements and are found toward the outer limits of thesubstrate whereas the rows comprise rib-like protruding elements and arefound toward the center of the substrate.

[0020]FIG. 9. is a plan view illustration of a preferred embodiment ofthe substrate of the present inventions showing rib-like rows ofprotruding elements.

[0021]FIG. 10. is a plan view illustration of a preferred embodiment ofthe substrate of the present inventions showing two patterns of secondregions arranged in waves.

[0022]FIG. 11. is a plan view illustration of a preferred embodiment ofthe substrate of the present inventions showing diamond shapedprotruding elements.

[0023]FIG. 12. is a cross sectional illustration of the substrateshowing the profile of the protruding elements.

DETAILED DESCRIPTION OF THE INVENTION

[0024] The present invention relates to substrates suitable for use ascleaning sheets in the removal of dust, lint, hair, grass, sand, foodcrumbs, dirt, soil and other matter of various size, shape, consistency,etc., from a variety of surfaces.

[0025] As a result of the ability of the substrates when used ascleaning sheets to reduce, or eliminate, by various means, includingremoval, collection and entrapment of dust, lint and other airbornematter from surfaces, as well as from the air, the sheets will providegreater reduction in the levels of such materials on surfaces and in theatmosphere, relative to other products and practices for similarcleaning purposes. The use of a low level of additive, uniformlyattached on at least one area of the substrate in an effective amount toimprove the adherence of soil, especially particulates, and especiallythose particulates that provoke an allergic reaction, provides asurprising level of control over soil adherence. At least in those areaswhere the additive is present on the substrate, the low level isimportant for such use, since, unlike traditional dusting operationswhere oils are applied as liquids, or as sprays, there is much lessdanger of creating a visible stain, especially on such non-traditionalsurfaces, when the substrate is used. The preferred structures alsoprovide benefits by trapping larger particles rather than abrading themto smaller sizes.

[0026] Consumers with allergies especially benefit from the use of thesubstrates herein, since allergens are typically in dust form and it isespecially desirable to reduce the level of small particles that arerespirable. For this benefit, it is important to use the substrates on aregular basis, and not just when the soil becomes visually apparent, asin prior art procedures.

[0027] The substrates of the present invention are suitable for use aspreferably disposable dry dusting sheets. The term “disposable” is usedherein to describe articles which are not intended to be laundered orotherwise restored or reused (i.e., they are intended to be discardedafter a single use, and, preferably, to be recycled, composted orotherwise disposed of in an environmentally compatible manner). Becauseof their single use nature, low cost materials and methods ofconstruction are highly desirable in disposable articles.

[0028] As used herein, the term “Z-dimension” refers to the dimensionorthogonal to the length and width of the substrate of the presentinvention. The Z-dimension usually corresponds to the thickness of thesubstrate. The term “X-Y dimension” thus refers to the plane orthogonalto the thickness of the substrate and thus usually corresponds to thelength and width, respectively, of the substrate.

[0029] As used herein, the term “layer” refers to a component of asubstrate whose primary dimension is X-Y, i.e., along its length andwidth. It should be understood that the term layer is not necessarilylimited to single layers or sheets of material. Thus the layer cancomprise laminates or combinations of several webs of the requisite typeof materials. Accordingly, the term “layer” includes the terms “layers”and “layered.”

[0030] For purposes of the present invention, an “upper” layer of asubstrate is a layer that is relatively further away from the surfacethat is to be cleaned (i.e., in the implement context, relatively closerto the implement handle during use). The term “lower” layer converselymeans a layer of a substrate that is relatively closer to the surfacethat is to be cleaned (i.e., in the implement context, relativelyfurther away from the implement handle during use). The term “inner”layer means a layer sandwiched between upper and lower layers.

[0031] By the term substrate it is meant a single fibrous web or alaminate of two or more webs, at least one of which being a fibrous web.And by the term web it is meant a fibrous web or a film (perforated,apertured, homogeneous, co-extruded or laminated).

[0032] By starting substrate it is meant the unformed substrate prior tomechanical manipulation thereof.

[0033] All percentages, ratios and proportions used herein are by weightunless otherwise specified.

[0034] The First and Second Regions

[0035] The substrates of the present invention comprise at least a firstregion and at least a second region. Preferably said substrates comprisea plurality of first and second regions. The substrates are designedsuch that said second regions are capable of greater geometricdeformation than said first regions. As used herein the term “geometricdeformation” refers to deformations of the substrate which are generallydiscernible to the normal naked eye when the substrate or articlesembodying the substrate are subjected to an applied elongation force.This is in contrast to “molecular-level deformation” which refers todeformation which occurs on a molecular level and is not discernible tothe normal naked eye. That is, even though one may be able to discernthe effect of molecular-level deformation, e.g., elongation of thesubstrate, one is not able to discern the deformation which allows orcauses it to happen.

[0036] The protruding elements of the second region permit greater“geometric deformation” which results in significantly less resistiveforces to an applied elongation than that exhibited by the first region.Types of geometric deformation include, but are not limited to bending,folding, unfolding, and rotating. The second regions of the substratescomprise protruding elements. As used herein, the term “protrudingelement” refers to an area of formation of ridges and/or furrows on thesurface of the substrate. The formation may be above or below the planeof the substrate and may be convex and/or concave. The protrudingelements may consists of only slight formation of the substrate,producing a mildly undulating surface. Preferably, the protrudingelements are more pronounced however and can be described as rib-likeand/or folding elements. Rib-like elements comprise a major axis and aminor axis defining an elongated cuboidal, ellipsoidal or other similarrib-like shape. The major axis and the minor axis of the protrudingrib-like elements may each be linear, curvilinear or a combination oflinear and curvilinear. Folding elements are greater in height than therib-like elements and tend to fold over partially or completelyobscuring an adjacent first region. In some instances the foldingelements may even partially obscure an adjacent protruding element. Eachsecond region of the substrate preferably comprises a plurality ofprotruding elements. More preferably the protruding elements in eachsecond region are contiguous with no unformed or first regions betweenthem.

[0037] The first regions are preferably and most typically visuallydistinct from the second regions. As used herein, the term “visuallydistinct” refers to features of the substrate which are readilydiscernible to the normal naked eye when the substrate or objectsembodying the substrate are subjected to normal use.

[0038] The first regions, when compared to the second regions, aresubstantially planar and unformed, comprising no protruding elements.The function of such areas is to provide integrity and strength to thesubstrate, especially during use. In comparison to the second regions,the first regions are less extensible and less deformable. Hence whilstthey may undergo geometric deformation, it is less than what isdiscernible with respect to the second regions of the substrate. Thefirst regions typically undergoes a molecular-level deformation only andthus the main role of the first regions of the substrate of the presentinvention is to limit the degree of extensibility of the substrate perse. The second regions by contrast comprise protruding elements whichare formed during the manipulation process described below. Theprotruding elements may appear visually like a region of corrugationcomprising ridges and furrows. Said protruding elements are capable ofgreater geometric deformation than the first regions owing to theexistence of the corrugated areas. When a force is applied to the secondregion of the substrate the protruding areas are stretched, extended ordeformed, becoming more planar, to the point of being substantiallyplanar like the first regions. Generally, the greater the size offormation of the protruding element the greater the level of geometricdeformation available. The increased three dimensionality provided bythe protruding elements of the second region provide a more efficientsurface for removal of dirt from a surface when compared to a uniformsubstrate. The elements conform more easily to irregularities in asubstantially planar surface (e.g. cracks, crevices, grout lines in tilefloors, etc.) thereby improving soil removal. The rib-like and/orfolding protruding elements of the substrates provide further improvedconformity to irregularities, especially the deeper irregularities.

[0039] The protruding elements in addition to benefits discussed abovealso provide a system for collection and entrapment of the soils. In apreferred execution, the protruding elements are folding elements asdescribed above, wherein the height of the protruding element is greaterthan the width. In a particularly preferred embodiment the second regioncomprises a plurality of contiguous folding protruding elements. In thisembodiment the protruding elements fold from the base of the element,covering or at least partially covering, the adjacent folding protrudingelement, thereby forming a closed or partially closed pocket between thefolding elements. In an alternative embodiment, the height of thefolding protruding element is greater than the width of an adjacentfirst region such that when the protruding element bends at the basethereof (i.e., fold over), it will cover, or at least partially cover,the adjacent first region, thereby forming a closed or partially closedpocket between the folding elements and the adjacent first region. Inanother execution, the height of the protruding element may cover, or atleast partially cover, the adjacent first region as well as a portion ofthe next protruding element. In this embodiment as with the precedingembodiment, the folded protruding element forms a closed or partiallyclosed pocket between the protruding elements and the adjacentprotruding element. With current “planar” dusting substrates, soil canbe lost from the substrate and/or redeposited when the user changeswiping direction (where potentially the most loss occurs when the wipingdirection is changed 180 degrees from previous wiping direction). Thebenefit of such folding elements in any of the above describedembodiments is that, during wiping, soil can be caught in the pocketsproduced by the folded protruding elements. When the user, changes orreverses the direction of cleaning, the protruding element flipsdirection or fold over to cover up the soil, thereby forming a substratepocket in which the soil can be protected from further possible lossand/or redeposition onto the floor. Additionally, when the substrateprotruding elements fold over to prevent soil loss, the other side ofthe protruding element and adjacent first region is exposed for furthersoil capture. An additional benefit of the above execution is that thesoil (e.g., dirt, small stones, etc.) is protected from potentiallydamaging (i.e., scratching) the surface that is being wiped since thefolded protruding element is now covering up the soil.

[0040] The first and second regions may be of any suitable shape andarranged in any desirable pattern. Examples of shapes may include strips(FIGS. 7 and 8), waves (FIG. 10) or blocks of first and second regionsintermittently spaced or islands of second regions in first regions orvice versa (FIG. 6). In one preferred embodiment strips of the firstregions are intermittently spaced between strips of second regions. Inanother preferred embodiment a portion of the first regions extend in afirst direction while the remainder of the first regions extend in asecond direction such that the first regions extending in differentdirections intersect one another at intervals. The second direction ispreferably substantially perpendicular to the first direction. In thisembodiment the first regions form a boundary completely surrounding thesecond regions, such that the overall pattern of first and secondregions formed resembles a plurality of diamonds (FIGS. 6 and 11). Thepercentage surface area coverage of the substrate of first and secondregions may vary according to the intended use and pattern desired.However, for the purpose of soil removal and collection, it is preferredthat the substrate comprises a greater surface area of second regionsthan first regions. The pattern of first and second regions may in factprovide a performance benefit. And so it is also envisaged that asubstrate for use as a cleaning sheet may comprise two or more differentpatterns across the surface of the substrate. In one example it may beenvisaged that a cleaning sheet substrate according to the presentinvention comprises folding protruding elements, preferably high and/orlarge folding protruding elements toward the center of the substratewhere larger dirt particulates can collect (instead of soil building upin the leading edges of the mop) and less pronounced ridge or rib-likeprotruding elements in the outer limits of the substrate (FIG. 7). Thisdesign of substrate offers (1) more efficient sheet utilization sincemore of the sheet is exposed for soil capture, (2) less opportunity forlarge particulate soil and/or soil agglomerates to collect (in piles)at/on the leading edges of the mop, and (3) less opportunity for a pileof dirt on the floor, since more of the soil is captured by the sheet.

[0041] Whilst the substrates of the present invention clearly compriseboth first and second regions, the substrates also comprise transitionalregions which are located at the interface between the first and secondregions. The transitional regions will exhibit complex combinations ofthe behavior of both the first region and the second region. It isrecognized that every embodiment of the present invention will havetransitional regions, however, the present invention is largely definedby the behavior of the substrate in distinctive regions. Therefore, thedescription of the present invention will be concerned with the behaviorof the substrate in the first and second regions only since the presentinvention is not significantly dependent upon the complex behavior ofthe substrate in the transitional regions

[0042] Method of Making the Substrates

[0043] The substrates of the present invention comprise first and secondregions. As discussed above the first regions are substantially unformedor planar, whereas the second regions are formed, comprising protrudingelements. The first and second regions of the substrate are formed froma starting substrate that is substantially planar. Said startingsubstrate is fed through a specially designed machinery which forms theprotruding elements of the substrate in predefined areas resulting inthe second regions of the substrate. The processes below are describedwith respect to manipulation of a starting substrate. Said substrateonce formed may be used as a cleaning sheet as is or may be a componentof a more complex laminate cleaning sheet. In the present description,by the term “formed” substrate (e.g. the substrate is formed) it ismeant that the starting substrate has been fed through the machinerydescribed and the protruding elements of the second regions of thesubstrate have been formed.

[0044] Referring now to FIG. 1, there is shown an apparatus 400 used toform the substrate 52 shown in FIG. 6. Apparatus 400, includesintermeshing plates 401, 402. Plates 401, 402 include a plurality ofintermeshing teeth 403, 404, respectively. Plates 401, 402 are broughttogether under pressure to form the substrate of the present invention.

[0045] Plate 402 includes toothed regions 407 and grooved regions 408both of which extend substantially parallel to the longitudinal axis ofthe plate 401. Within toothed regions 407 of plate 402 there are aplurality of teeth 404. Plate 401 includes teeth 403 which mesh withteeth 404 of plate 402. When a substrate is formed between plates 401,402 the portions of the starting substrate which are positioned withingrooved regions 408 of plate 402 and teeth 403 on plate 401 remainundeformed. These regions correspond with the first regions 60 of thesubstrate 52 shown in FIG. 6. The portions of the starting substratepositioned between toothed regions 407 of plate 402, (which compriseteeth 404), and teeth 403 of plate 401 are incrementally formed creatingthe second regions and/or the protruding elements 74 in the secondregions 66 of the substrate 52.

[0046] The method of formation can be accomplished in a static mode,where one discrete portion of a substrate is formed at a time. Anexample of such a method is show in FIG. 2. A static press indicatedgenerally as 415 includes an axially moveable plate or member 420 and astationary plate 422. Plates 401 and 402 are attached to members 420 and422, respectively. While plates 401 and 402 are separated, the startingsubstrate is introduced between the plates 401 and 402. The plates arethen brought together under a pressure indicated generally as “P”. Theupper plate 401 is then lifted axially away from the plate 402 allowingthe formed substrate to be removed from between the plates 401 and 402.

[0047] Alternatively, the method of formation can be accomplished usinga continuous, dynamic press (FIG. 3) for intermittently contacting themoving starting substrate and forming the starting substrate into theformed substrate of the present invention. The starting substrate 406 isfed between plates 401 and 402 in a direction generally indicated byarrow 430. Plate 401 is secured to a pair of rotatably mounted arms 432,434 which travel in a clockwise direction and which move plate 401 in aclockwise motion. Plate 402 is connected to a pair of rotary arms 436,438 which travel in a counter clockwise direction moving plate 402 in acounter clockwise motion. Thus, as the starting substrate 406 movesbetween plates 401 and 402 in the direction indicated by the arrow 430 aportion of the starting substrate between the plates is formed and thenreleased such that the plates 401 and 402 may come together and formanother section of starting substrate 406. This method has the benefitof allowing virtually any pattern of any complexity to be formed in acontinuous process e.g. unidirectional, bi-directional andmulti-directional patterns.

[0048]FIG. 4 shows another apparatus generally indicated as 500 forcontinuously forming the substrate of the present invention. Apparatus500 includes a pair of rolls 502, 504. Roll 502 includes a plurality oftoothed regions 506 and a plurality of grooved regions 508 that extendsubstantially parallel to a longitudinal axis running through the centerof the cylindrical roll 502. Toothed regions 506 include a plurality ofteeth 507. Roll 504 includes a plurality of teeth 510 which mesh withteeth 507 on roll 502. As a starting substrate is passed betweenintermeshing rolls 502 and 504, the grooved regions 508 will leaveportions of the starting substrate unformed producing the first regionsof the substrate of the present invention. The portion of the startingsubstrate passing between toothed regions 506 and 510 will be formed byteeth 507 and 510, respectively, producing the second regions of thesubstrates of the present invention, and more specifically theprotruding elements of the present invention.

[0049] Alternatively roll 504 may consist of soft rubber. As thestarting substrate is passed between toothed roll 502 and rubber roll504 the starting substrate is mechanically formed into the patternprovided by toothed roll 502. The substrate within the grooved regions508 will remain unformed, while the starting substrate within thetoothed regions 506 will be formed producing the second regions of thesubstrate of the present invention, and more specifically the protrudingelements of the present invention.

[0050] Referring now to FIG. 5 there is shown an alternative apparatusgenerally indicated as 550 for forming the starting substrate into aformed substrate. Apparatus 550 includes a pair of rolls 552, 554. Rolls552 and 554 each have a plurality of toothed regions 556 and groovedregions 558 extending about the circumference of rolls 552, 554respectively. As the starting substrate passes between 552, 554 thegrooved regions 558 will leave portions of the starting substrateunformed, while the portions of the starting substrate passing betweentoothed regions 556 will be formed producing the second regions of thesubstrates of the present invention, and more specifically theprotruding elements of the present invention.

[0051] The height and frequency of the protruding elements of thesubstrate is dependent on: (1) tooth pitch meaning the distance fromtooth tip to tooth tip; (2) depth of engagement (see distance DOE, FIG.4a) meaning the extent to which the toothed and grooved regions of thetwo rolls overlap; and (3) substrate properties (e.g., basis weight,caliper, number of fibers, fiber diameter, fiber types, etc.). Duringthe mechanical manipulation process, the starting substrate is travelingbetween the upper and lower rolls. While the starting substrate travelsbetween the rolls described, the starting substrate becomes “locked”between the tips of teeth on either roll (i.e., when the startingsubstrate cannot move in the direction perpendicular to movement ofstarting substrate through the rolls). From a hardware point of view,the point when starting substrate “lock up” occurs depends on (1) thetooth pitch and (2) depth of engagement. Typically, the smaller thetooth pitch and larger the depth of engagement, yields an earlierstarting substrate “lock” occurrence and thus taller and more frequentprotruding elements. The greater height and frequency of the protrudingelements results in a substrate with greater potential for substrategeometric deformation. From a starting substrate point of view, thethicker the starting substrate, the more fibers, and the greater thebasis weight, also, yields an earlier starting substrate “lock”occurrence and thus as above, results in a substrate with greaterpotential for substrate geometric deformation. Hence in order to producea substrate with protruding elements, but not being bound to a specifictooth pitch and starting substrate, the depth of engagement of thetoothed and grooved regions is preferably in excess of 0.01 inches.

[0052] It is clear from the above process that the first regions resultfrom contact with the grooved regions of the roll and are thus unformedand substantially planar. However it may also be envisaged that thefirst regions comprise a comparatively minor level of formation. In thiscase, the grooves of the roll may be shallow or comprise an irregularsurface such that when the starting substrate is fed through themachinery, the first regions comprise a corresponding irregular surface.Alternatively it may be envisaged that the starting substrate may be fedthrough a series of manipulation processes. In at least one of theseprocesses the first regions are manipulated so as to be minorly formed.Subjecting the starting substrate to a series of formation manipulationprocesses allows the manufacturer to produce a substrate comprising morethan one pattern. Thus in a first pattern is formed during a firstmanipulation step and a second pattern is formed during a secondmanipulation step. It is also conceivable that more than two patternsare applied to the substrate.

[0053] As discussed above the use of more than one pattern can provide aperformance as well as aesthetic benefit. In addition minor deformationof the first regions may in fact provide a further performance benefitin that said first regions will have even lower density, thus be evenmore suitable for capturing soil. In all such situations however, saidsecond regions are always visually distinct from said first regions.

[0054] In order to make the process feasible for mass production ofcommercial interest the process must run at a minimum speed ofapproximately 50 feet/minute. Suitable starting substrates for use insuch high speed manipulation of the web(s) are those that can bemanipulated at said minimum speed without tearing, perforating, creatingholes and/or substantially unacceptable thin regions (i.e. less opaque,lower fiber concentration) in the substrate.

[0055] The Substrate Composition

[0056] The first and second regions are preferably comprised of the samematerial composition. The substrate of the present invention is madefrom at least one fibrous web. It is envisaged that the substrateaccording to the present invention may be a single fibrous web that hasundergone the mechanical manipulation to form the first and secondregions of the substrate. Alternatively it can equally be envisaged thatthe substrate may be composed of a laminate of at least two, morepreferably at least three or even more webs, wherein at least one web isa fibrous web. The laminate of webs may be compiled prior to beingsubjected to the mechanical manipulation to form the first and secondregions of the substrate as above. Alternatively the laminate of websmay be compiled at the point where the webs are fed into the machinery.Further still, it can be envisaged that the substrate composed of asingle fibrous web or a laminate of two or more webs is subjected to themechanical manipulation above, and is then used as a component of a morecomplex cleaning sheet structure.

[0057] The substrates of the present invention have low density, meaningthat the density of the substrate is no more than 0.15 g/cm³, morepreferably no more than 0.12 g/cm³, more preferably no more than 0.1g/cm³ and most preferably no more than 0.09 g/cm³. Lower densitysubstrates have greater pore volume and are therefore more suitable forcollection and entrapment of soil. In addition to the increase in volumefor storing said soil, the lower density substrate also results in thefibers entangling with soil particles, etc., further prohibitingredeposition of the soil on the surface cleaned.

[0058] The substrates of the present invention are preferably loftymeaning that they have caliper of no less than 0.7 mm, more preferablyno less than 0.8 mm and most preferably no less than 0.9 mm. Thesubstrates of the present invention are also preferably resilient,meaning that the substrate substantially reforms its original shape andcaliper once a force has been applied to the substrate and thenreleased. One measure of substrate resiliency is the amount of thicknessrecovery (caliper rebound) exhibited by the substrate once a pressureload (0.066 psi) is removed (measured after 3 min). The substrates ofthe present invention preferably exhibit caliper rebound of greater than65%, more preferably greater than 70%, and most preferably greater than75% of its original caliper. The test methodology for measuring caliperrebound is detailed hereafter. It is also preferable that the protrudingelements of the regions of the substrate are resilient, not only so thatthe substrate can be used to full capacity, but also so as to ensurethat the protruding elements can rebound after having been compressedduring packaging and storage.

[0059] The substrates of the present invention are preferably made usinglightly bonded/entangled webs made by various nonwovens processesincluding, but not limited to air laid, carded, carded thermal bonded,carded chemical bonded, carded through air bonded, melt blown, spunbond,spunlace, and combinations thereof. By ‘lightly bonded/entangled’ it ismeant that (1) the fibers are loosely or not bonded/entangled togetherthroughout the thickness (z-plane of the web) of the web and/or (2) thedistance between bond/entanglement points are widely spaced apart fromeach other. The substrates of the present invention preferably have abasis weight of from 10 to 120 grams/meter², more preferably from 15 to100 grams/meter² and most preferably from 20 to 90 grams/meter².

[0060] To determine which starting substrates are capable of beingmanipulated using the above described process, the starting substratesare subjected to the above process of manipulation to determine whetherthe process will tear, perforate, create holes and/or substantiallyunacceptable thin regions (i.e., less opaque, lower fiber concentration)in the substrate. The mechanical manipulation process parameters,meaning speed of mechanical manipulation, depth of engagement betweentwo corresponding rolls, tooth pitch, influences the ability of thestarting substrate to withstand the rigors of the mechanicalmanipulation. Due to this complexity, the method of selecting startingsubstrates is to subject the starting substrate of interest to themechanical manipulation process to determine if the formed substratedelivers the desired results. Depending on the results of theseexperiments, various mechanical manipulation process parameters can beadjusted to aid in making a selected starting substrate useful in thisprocess.

[0061] Preferred starting substrates comprise webs that can extend orelongate quickly without tearing, perforating, creating holes and/orsubstantially unacceptable thin regions. Typically the preferred websshould be able to extend about 200% in about 0.01 seconds or less.

[0062] Preferred substrate of the present invention comprising at leasttwo different fiber types. By that it is meant that the substratecomprises at least two fiber types that differ from one another by fiberlength, fiber diameter (denier), fiber chemistry, fiber finish andmixtures thereof.

[0063] Fibers suitable for forming the webs used in the production ofthe substrates of the present invention are selected from the groupconsisting of: wood pulp, cotton, wool, and the like, as well asbiodegradable fibers, such as polylactic acid fibers, and syntheticfibers such as polyolefins (e.g., polyethylene and polypropylene),polyesters, polyamides, synthetic cellulosics (e.g., RAYON®, Lyocell),cellulose acetate, bicomponent fibers meaning fibers comprising asheath/core or side by side construction of at least two differentmaterials; and blends thereof and films selected from the groupconsisting of polyolefin (e.g., polyethylene and polypropylene),polyesters, polyamides, cellulose acetate, glycine, ethyl vinyl acetate,biodegradable films such as polylactic acid and laminates of films(co-extruded films) and mixtures thereof. Preferred fibers for makingthe substrates of the present invention are synthetic and bicomponentmaterials, which can be in the form of carded, carded thermal bonded,carded chemical bonded, carded through air bonded, hydroentangled,spunbond, meltblown, airlaid, or other structures.

[0064] In a particularly first preferred embodiment, the substrate iscomposed of a single fibrous web made from a spunbond web. Howevercurrently available spunbond webs are often not suitable to withstandthe rigors of the mechanical forces imparted to the web during themechanical manipulation to produce the second region(s) and specificallythe protruding elements without the web tearing or perforating. Intypical spunbond webs, the fibers are bonded throughout the Z dimensionof the web. Hence, in a preferred aspect of the present invention thesubstrate is made from a single fibrous web made by the spunbond processwhich has been ‘lightly bonded’ only. With regard to spunbond webs thisspecifically means that only a portion of the outer surface fibers ofthe web is bonded, leaving the interior web fibers substantially notbonded. Typically, these bonds are imparted to the fibrous web bypassing the web through heated embossed calendar rolls. The extent ofweb bonding can be adjusted using a number of variables; for exampleemboss pattern and embossed surface area, temperature, nip pressure, andresidence time in the embossed calendar rolls. A method for determiningwhether a spunbond web is lightly bonded is to rub the web between thumband finger using average pressure for about 30 seconds. If the webbegins to show signs of piling, then it is suitably lightly bonded.

[0065] A preferred spunbond web is made using bicomponent fibers.Preferably said bicomponent fibers are selected from the groupconsisting of polyethylene/polyproylene, polyethylene/polyethyleneterephthalate, polyethylene/nylon and combinations thereof. A preferredspunbond web was sourced from BBA Nonwovens, Washougal, Wash. The webwas a modified Softspan (tradename) spunbond web, with increased basisweight (range of 30-80 gsm), reduced embossing parameters (nip pressure,emboss temperature) such that the starting substrate when rubbed willreadily pill, modified fiber denier (in the range of 1.8 to 5.8 dpf; andmixtures thereof), and modified core/sheath bicomponent ratio in therange of 50/50 to 30/70 PE/PP.

[0066] The basis weight of such spunbond substrates is preferably fromabout 10 to about 120 grams/meter², more preferably from about 15 toabout 100 grams/meter², and most preferably from about 20 to about 90grams/meter².

[0067] In another preferred second embodiment the substrate is alaminate of at least two fibrous webs. The webs are layered one on topof the other forming upper, lower and optionally inner layers. Fibersparticularly suitable for forming such webs include, for example,natural fibers, e.g. wood pulp, cotton, wool, and the like, as well asbiodegradable fibers, such as polylactic acid fibers, and syntheticfibers such as polyolefins (e.g., polyethylene and polypropylene),polyesters, polyamides, synthetic cellulosics (e.g., RAYON®, Lyocell),cellulose acetate, bicomponent fibers, and blends thereof. The webs maybe in the form of carded, spunbonded, meltblown, spunlaced, airlaid,carded thermal bonded, carded chemical bonded, carded through airbonding or other structures. The webs once formed are preferablyhydroentangled as is well known in the art. As used herein, the term“hydroentangle” means generally a process of treatment of a startingsubstrate wherein a layer of loose fibrous material (e.g., polyester) issupported on an apertured member and is subjected to water pressuressufficiently great to cause the individual fibers to mechanicallyentangle with other fibers and possibly other web layers of a substrate.The apertured member can be made from a woven screen, a perforated metalplate, etc.

[0068] Preferred starting materials for making the substrates of thisembodiment are synthetic materials, which can be in the form of carded,spunbonded, meltblown, airlaid, spunlaced, carded thermal bonded, cardedchemical bonded, carded through air bonded or other structures.Particularly preferred are carded webs, especially carded webs made frompolyester, bicomponent fibers or mixtures thereof.

[0069] A preferred substrate comprises first fibers and second fibershaving different denier. The substrate may comprise a web homogeneouslycomprising first fibers and second fibers or may comprise a first webcomprising first fibers and a second web comprising second fiberswherein said first fibers and said second fibers have different denier.The fibers of the webs according to this embodiment preferably havedenier of less than 15 denier, more preferably from about 0.3 to about12, and most preferably from about 0.5 to about 10. The difference indenier between the first and second fibers should preferably be at leastabout 0.3, more preferably at least about 0.7, most preferably at leastabout 1 denier. In a preferred embodiment, the first fibers will have adenier of from about 0.5 to about 5 and the second fibers will have adenier of from about 1 to about 10. The substrates will preferablycomprise a ratio of first fibers to second fibers of from about 100:1 toabout 1:100, more preferably from about 10:1 to about 1:20, and morepreferably from about 1:5 to about 1:10, by weight. The thickness of thesubstrate can be important for both cleaning performance and aestheticsreasons. The combination of fibers having relatively high denier withfibers having relatively low denier can provide the cleaning sheet withthe desired caliper. Moreover a substrate comprising fibers havingdifferent denier can also provide substrate resilience and particleentrapment properties. Larger denier fibers provide rigidity to thesubstrate, improving substrate resilience and tend to be useful inentrapment of larger particle sizes. Smaller denier fibers by contrasttend to be useful in entrapment of smaller particle sizes, it istherefore useful to be able to combine both characteristics and thusincrease the range of particles that can be entrapped by the substrate

[0070] The upper and/or lower layers of webs whilst providingcharacteristics suitable for cleaning, collection and entrapment ofsoil, are often not particularly suitable to withstand the rigor of themechanical manipulation of the process preferred to produce the firstand second regions of the substrate. It is therefore preferable toincorporate: (i) a reinforcing web to provide further strength andintegrity to the substrate; (ii) an extensible web to provide greaterextensibility of the substrate before breaking; or (iii) a reinforcing,extensible web which provides characteristics of both of webs (i) and(ii) as an inner layer.

[0071] A reinforcing web is defined as a web which provides additionalstrength and integrity over that provided by other webs of thesubstrate. A reinforcing web is especially preferred wherein the upperand/or lower layer comprises carded staple fibers, such as carded staplepolyester fibers. Carded staple fibers, while being particularlyeffective for removing particulate matter from surfaces, can result in acleaning sheet without sufficient strength and integrity. Thereinforcing web tends to provide enhanced strength and integrity to theresulting substrate, which is especially important when it is used forcleaning household surfaces such as hardwood floors, ceramic tile (withgrout), furniture surfaces, and the like. The reinforcing web typicallycomprises webs selected from the group consisting of carded thermalbonded, carded chemical bonded, carded thorough air bonded, meltblown,spunbonded, hydroentangled, extruded films and mixtures thereof. Thereinforcing web is preferably free of non-random perforations or openareas. A preferred reinforcing web herein will preferably use fibershaving a denier of less than 15, more preferably from about 0.3 to about12, and even more preferably from about 0.4 to about 10. A preferredreinforcing web is a 100% polypropylene spunbond.

[0072] An extensible web is defined as a web which provides additionalextensibility/stretch over that provided by other webs of the substrate.Incorporating such an extensible web into a substrate, enable thesubstrate to be extendable without tearing, perforating, creating holesand/or unacceptably thin regions. Incorporation of an extensible webinto the substrate therefore results in the ability of the manufacturerto use higher manufacturing speeds and thus increase yield. Such asubstrate will also exhibit a greater degree of geometric deformation.An extensible web is especially preferred wherein the upper and/or lowerlayer comprises carded staple fibers, such as carded staple polyesterfibers. The extensible web typically comprises webs selected from thegroup consisting of carded thermal bond, carded chemical bond, cardedthrough air bonded, meltblown, spunbonded, hydroentangled, and mixturesthereof. In a preferred embodiment the extensible web is made of frompolyethylene (PE), polypropylene (PP), and bicomponent fibers (PE/PP,PE/PET, PE/Nylon), Nylon and mixtures thereof. The preferred extensibleweb herein will preferably use fibers having a denier of less than 15,more preferably from about 0.3 to about 12, and even more preferablyfrom about 0.4 to about 10. A preferred extensible web is a spunbond webmade from bicomponent fibers 50% PE/50% PP.

[0073] A reinforcing extensible web comprises characteristics of boththe reinforcing and extensible webs. A preferred example of such a webis an area bonded spunbond fibrous web having a basis weight of 17 g/m²and comprising polyester fibers having a denier per filament of about6.0. Said web is available form BBA under the tradename Remay 1054W.

[0074] When the substrate is a laminate of two or more webs the basisweight of the substrate is preferably from about 10 to about 120grams/meter², more preferably from about 15 to about 100 grams/meter²,and most preferably from about 20 to about 90 grams/meter².

[0075] The substrate of this embodiment preferably comprises at leastthree fibrous webs. The substrate comprises two fibrous webs and areinforcing, extensible or reinforcing extensible fibrous web. The websare preferably positioned such that the two fibrous webs are the upperand lower layer and the reinforcing web is the inner layer. The fibrouswebs preferably both comprise carded staple fibers, and the reinforcingfibrous web preferably comprises spunbond or thermally bonded fibers.All three webs are then hydroentangled to form the substrate.

[0076] In another preferred embodiment the substrate comprises threewebs, the upper and lower webs being fibrous in nature and the inner webbeing a film.

[0077] The present substrates can further comprise four, five, six, ormore webs (or layers). In the preferred embodiments that comprise anupper and lower fibrous web and an inner fibrous web selected from thosediscussed above, the inner layer web will generally have a basis weightthat is from about 10% to about 85%, preferably from about 15% to about80%, and more preferably from about 20% to about 75%, of the totalaggregate basis weight of the substrate.

[0078] The three dimensionality of the substrate of the presentinvention can be described in terms of the “Average Height Differential”of a peak of a protruding element and an adjacent valley, as well as interms of the “Average Peak-to-Peak Distance” between peaks of adjacentprotruding elements. Referring to FIG. 12, the height differential withrespect to a peak 101A/valley 101B pair is the distance H. Thepeak-to-peak distance between an adjacent pair of peaks 101A and 102A isindicated as distance D. The “Average Height Differential” and the“Average Peak-to-Peak Distance” of the protruding element of thesubstrate are measured as set forth below in the “Test Methods”described hereinafter. The “Surface Topography Index” of the substrateis the ratio obtained by dividing the Average Height Differential of thesubstrate by the Average Peak to Peak Distance of the substrate.

[0079] It will be apparent to one skilled in the art that there will berelatively small regions of peaks and valleys that are not significantenough to be considered as providing macroscopic three dimensionality.Such fluctuations and variations are a normal and expected result of themanufacturing process and are not considered when measuring SurfaceTopography Index.

[0080] Without being limited by theory, it is believed that the SurfaceTopography Index is a measure of the effectiveness of themacroscopically three dimensional surface in receiving and containingmaterial in the valleys of the surface. A relatively high value ofAverage Height Differential for a given Average Peak to Peak Distanceprovides deep, narrow valleys which can trap and hold materials.Accordingly, a relatively high value of Surface Topography Index isbelieved to indicate effective capture of materials during wiping.

[0081] The Average Peak to Peak Distance of the protruding elements ofthe second region will be at least about 0.5 mm, more preferably atleast about 1.0 mm, and still more preferably at least about 1.5 mm. Inone embodiment, the Average Peak to Peak distance is from about 0.5 toabout 30 mm, particularly from about 1.0 to about 25 mm, moreparticularly from about 1.5 to about 20 mm. The Surface Topography Indexof the second region will preferably be from about 0.01 to about 100,more preferably from about 0.05 to about 75, still more preferably fromabout 0.75 to about 60, still more preferably from about 0.8 to about50. While not critical, the second region will preferably have anAverage Height Differential of at least about 0.3 mm, more preferably atleast about 0.5 mm, and still more preferably at least about 0.7 mm. TheAverage Height Differential of the second region will typically be fromabout 0.3 to about 12 mm, more typically from about 0.5 to about 10 mm.

[0082] Referring to FIG. 6, substrate 52 includes distinct regions; aplurality of first regions 60 and a plurality of second regions 66.Substrate 52 also includes transitional regions 65 which are located atthe interface between the first regions 60 and the second regions 66.However as discussed above the present invention is largely defined bythe behavior of the substrate in distinctive regions (e.g., firstregions 60 and second regions 66). Therefore, the present descriptionwill be concerned with the behavior of the substrate in the firstregions 60 and the second regions 66 only.

[0083] Substrate 52 has a first surface, (facing the viewer in FIG. 6),and an opposing second surface (not shown). In the preferred embodimentshown in FIG. 6, the substrate includes a plurality of first regions 60and a plurality of second regions 66. A portion of the first regions 60,indicated generally as 61, are substantially linear and extend in afirst direction. The remaining first regions 60, indicated generally as62, are substantially linear and extend in a second direction which ispreferably substantially perpendicular to the first direction. While itis preferred that the first direction be perpendicular to the seconddirection, other angular relationships between the first direction andthe second direction may be suitable so long as the first regions 61 and62 intersect one another. Preferably, the angles between the first andsecond directions ranges from about 45° to about 1350, with 900 beingthe most preferred. The intersection of the first regions 61 and 62forms a boundary, indicated by phantom line 63 in FIG. 6, whichcompletely surrounds the second regions 66.

[0084] Preferably, the width 68 of the first regions 60 is from about0.01 inches to about 1 inches, and more preferably from about 0.03inches to about 0.75 inches. However, other width dimensions for thefirst regions 60 may be suitable. Because the first regions 61 and 62are perpendicular to one another and equally spaced apart, the secondregions have a square shape. However, other shapes for the second region66 are suitable and may be achieved by changing the spacing between thefirst regions and/or the alignment of the first regions 61 and 62 withrespect to one another, as discussed above. The second regions 66 have afirst axis 70 and a second axis 71. The first axis 70 is substantiallyparallel to the longitudinal axis (L) of the substrate 52, while thesecond axis 71 is substantially parallel to the transverse axis (T) ofthe substrate 52.

[0085] In the illustrated embodiment, the substrate 52 has been “formed”such that the substrate 52 exhibits a resistive force along an axis,which in the case of the illustrated embodiment is substantiallyparallel to the transverse axis of the substrate, when subjected to anapplied axial elongation force in a direction substantially parallel tothe transverse axis (T). As used herein, the term “formed” refers to thecreation of a desired structure or geometry upon a substrate that willsubstantially retain the desired structure or geometry when it is notsubjected to any externally applied elongations or forces. A substrateof the present invention is comprised of a plurality of first regionsand a plurality of second regions, wherein the first regions arevisually distinct from the second regions.

[0086] In the preferred embodiment shown in FIG. 6 the first regions 60are in substantially the same condition before and after the formationstep undergone by substrate 52. The second regions 66 include protrudingelements, preferably a plurality of said elements, more preferably saidelements are rib-like 74 and/or folding elements. Rib-like protrudingelements 74 have a first or major axis 76 which is substantiallyparallel to the longitudinal axis of the web 52 and a second or minoraxis 71 which is substantially parallel to the transverse axis of theweb 52.

[0087] The protruding elements 74 in the second region 66 may beseparated from one another by unformed areas or simply spacing areas.Preferably, the protruding elements 74 are adjacent to one another andare separated by an unformed area of less than 0.10 inches as measuredperpendicular to the major axis 76 of the protruding elements 74, andmore preferably, the protruding elements 74 are contiguous having nounformed areas between them.

[0088] Optional Additive Material

[0089] The cleaning performance of any of the substrates of the presentinvention can be further enhanced by treating the substrates with any ofa variety of additives, including surfactants or lubricants, thatenhance adherence of soils to the substrate. When utilized, suchadditives are added to the substrate at a level sufficient to enhancethe ability of the substrate to adhere soils. Such additives arepreferably applied to the substrate at an add-on level of at least about0.01%, more preferably at least about 0.1%, more preferably at leastabout 0.5%, more preferably at least about 1%, still more preferably atleast about 3%, still more preferably at least about 4%, by weight.Typically, the add-on level is from about 0.1 to about 25%, morepreferably from about 0.5 to about 20%, more preferably from about 1 toabout 15%, still more preferably from about 3 to about 10%, still morepreferably from about 4 to about 8%, and most preferably from about 4 toabout 6%, by weight. A preferred additive is a wax or a mixture of anoil (e.g., mineral oil, petroleum jelly, etc.) and a wax. Suitable waxesinclude various types of hydrocarbons, as well as esters of certainfatty acids (e.g., saturated triglycerides) and fatty alcohols. They canbe derived from natural sources (i.e., animal, vegetable or mineral) orcan be synthesized. Mixtures of these various waxes can also be used.Some representative animal and vegetable waxes that can be used in thepresent invention include beeswax, camauba, spermaceti, lanolin, shellacwax, candelilla, and the like. Representative waxes from mineral sourcesthat can be used in the present invention include petroleum-based waxessuch as paraffin, petrolatum and microcrystalline wax, and fossil orearth waxes such as white ceresine wax, yellow ceresine wax, whiteozokerite wax, and the like. Representative synthetic waxes that can beused in the present invention include ethylenic polymers such aspolyethylene wax, chlorinated naphthalenes such as “Halowax,”hydrocarbon type waxes made by Fischer-Tropsch synthesis, and the like.

[0090] When a mixture of mineral oil and wax is utilized, the componentswill preferably be mixed in a ratio of oil to wax of from about 1:99 toabout 99:1, more preferably from about 1:99 to about 10:1, still morepreferably from about 1:99 to about 3:7, by weight. In a particularlypreferred embodiment, the ratio of oil to wax is about 3;7, by weight,and the additive is applied at an add-on level of about 5%, by weight. Apreferred mixture is a 3:7 mixture of mineral oil and paraffin wax.

[0091] Particularly enhanced cleaning performance is achieved whenmacroscopic three-dimensionality and additive are provided in a singlesubstrate. As discussed hereinbefore, these low levels are especiallydesirable when the additives are applied at an effective level andpreferably in a substantially uniform way to at least one discretecontinuous area of the sheet. Use of the preferred lower levels,especially of additives that improve adherence of soil to the sheet,provides surprisingly good cleaning, dust suppression in the air,preferred consumer impressions, especially tactile impressions, and, inaddition, the additive can provide a means for incorporating andattaching perfumes, pest control ingredients, antimicrobials, includingfungicides, and a host of other beneficial ingredients, especially thosethat are soluble, or dispersible, in the additive. These benefits are byway of example only. Low levels of additives are especially desirablewhere the additive can have adverse effects on the substrate, thepackaging, and/or the surfaces that are treated.

[0092] Application of these additives preferably means applying at leasta substantial amount of the additive at points “inside” the substratestructure. It is an especial advantage of the three dimensionalstructure of the present substrate that the amount of additive that isin contact with the surface being cleaned and/or the package, islimited, so that additives that could cause damage, or interfere withthe function of the surface, can only cause limited, or no, adverseeffects. It is also preferred that additive is applied to the peaksand/or base of the protruding elements of the present substrates. Thepresence of the additive inside and outside the substrate structure isbeneficial in that soil adheres more readily to and is less likely to bedisplaced from areas of substrate where additive has been applied.

[0093] Packaging

[0094] The invention also comprises packages containing cleaning sheetssubstrates of the present invention. The packages being in associationwith information that will inform the consumer, by words and/or bypictures, that use of the sheets will provide cleaning benefits whichinclude soil (e.g., dust, lint, etc.) removal and/or entrapment and thisinformation can comprise the claim of superiority over other cleaningproducts. In a highly desirable variation, the package bears theinformation that informs the consumer that the use of the cleaning sheetprovides reduced levels of dust and other airborne matter in theatmosphere. It is very important that the consumer be advised of thepotential to use the sheets on non-traditional surfaces, includingfabrics, pets, etc., to ensure that the full benefits of the sheets isrealized. Accordingly, the use of packages in association withinformation that will inform the consumer, by words and/or by pictures,that use of the compositions will provide benefits such as improvedcleaning, reduction of particulate soil in the air, etc. as discussedherein, is important. The information can include, e.g., advertising inall of the usual media, as well as statements and icons on the package,or the sheet itself, to inform the consumer.

[0095] Cleaning Implements

[0096] The substrates of the present invention are suitable for use ascleaning sheets. When used for cleaning surfaces such as floors, animplement may be useful, so that the user does not have to lowerthemselves to the floor. In this regard, it is envisaged that thesubstrates of the present invention are suitable for use with a cleaningimplement. Typical cleaning implements comprise a handle, a mop head,and a means of fastening, preferably removable fastening, of thecleaning sheet substrate of the present invention to the mop head.

[0097] The handle of the cleaning implement comprises any elongated,durable material that will provide ergonomically practical cleaning. Thelength of the handle will be dictated by the end-use of the implement.To facilitate ease of use, the mop head can be pivotably attached to thehandle using known joint assemblies. Any suitable means for attachingthe cleaning sheet to the mop head can be utilized, so long as thecleaning sheet remains affixed during the cleaning process. Examples ofsuitable fastening means include clamps, hooks & loops (e.g., VELCRO®),and the like. In a preferred embodiment, the mop head will comprise“grippers” on its upper surface to keep the sheet mechanically attachedto the mop head during the rigors of cleaning. The grippers will alsoreadily release the sheet for convenient removal and disposable.Preferred grippers are described in co-pending U.S. application Ser. No.09/374,714 filed Aug. 13, 1999 by Kingry et al., which is incorporatedherein by reference.

[0098] To further improve glide characteristics and cleaning performancewhen a present cleaning sheet is attached to a cleaning implement, themop head of the cleaning implement can have curved profile on the bottomsurface of the mop head. Suitable mop heads have curved bottom surfacesare described in co-pending U.S. application Ser. No. 09/821,953 filedMar. 30, 2001 by Kacher et al., which is incorporated herein byreference.

[0099] Suitable cleaning implements are shown in U.S. Design Pat. Nos.D409,343; and D423,742; which are incorporated herein by reference.

EXAMPLES

[0100] The following Examples I-III are non-limiting examples of thesubstrates of the present invention. Each substrate once produced issubjected to the process described above to form the first and secondregions of the substrates. Examples of suitable patterns are shown inFIGS. 6 to 11.

[0101] Examples I and II describe a substrate comprising a first fibrousweb, a second fibrous web, and a third reinforcing fibrous web, whereinthe first and second fibrous webs are the same material. The first,second, and third fibrous webs are placed on top of a forming belt, withthe third reinforcing fibrous web being positioned in between the firstfibrous web and the second fibrous web. The forming belt is a 100×90mesh screen. The webs are then hydroentangled and dried. The waterentangling process causes the fibers of the first and second fibrouswebs to become intertangled and to also become intertangled with thefibers of the reinforcing fibrous web. The substrate is then optionallysurface coated (by, e.g., printing, spraying, etc.) with 5%, by weight,of a 3:7 mixture of mineral oil and paraffin wax. Finally the startingsubstrate prepared as above is subjected to the forming processdescribed herein resulting in a substrate with first and second regionscomprising protruding elements.

EXAMPLE I

[0102] First/Second Carded fibrous web having a basis weight of 20 g/m²Fibrous Web: and comprising staple polyester fibers having a diameter of1.5 dpf and length of 37 mm (Wellman Type 203) Third Reinforcing Lightlythermally point bonded spunbond fibrous web Fibrous Web: having basisweight of 30 g/m² and comprising 50/50 polyethylene/polypropylenebicomponent fibers (sheath/core) having a nominal diameter of about 3.1.Total Aggregate 70 g/m² Basis Weight: Substrate Pattern: Large DiamondCaliper under 1.87 mm 0.035 psi load: Peak to Peak 4.32 mm AverageHeight 2.40 mm Differential Topography 0.55 Index:

EXAMPLE II

[0103] First/Second Carded fibrous web having a basis weight of 25.5g/m² Fibrous Web: and comprising staple polyester fibers having adiameter of 1.5 dpf and length of 37 mm (Wellman Type 203) ThirdReinforcing Area bonded spunbond fibrous web having a basis Fibrous Web:weight of 17 g/m² and comprising polyester fiber having a denier perfilament of about 6.0. (Remay 1054 W) Total Aggregate 68 g/m² BasisWeight: Substrate Pattern: Large Diamond Caliper under 3.26 mm 0.035 psiload: Peak to Peak 4.15 mm Distance Average Height 3.25 mm DifferentialTopography 0.78 Index

EXAMPLE III

[0104] Single fibrous web: lightly thermally point bonded spunbondcomprising 50/50 polyethylene/polypropylene bicomponent fibers(sheath/core) having a nominal diameter of about 3.1 with 18% bond area.(modified Softspan from BBA, Washougal, Wash.) Substrate Basis Weight:  72 g/m² Caliper under 0.035 psi load: 1.76 mm Substrate Pattern StyleLarge Diamond Peak to Peak Distance 3.63 mm Average Height Differential1.67 mm Topography Index 0.46

[0105] Test Methodology

[0106] A. Average Height Differential

[0107] Average Height Differential is determined by using a videomeasuring system, SmartScope (serial number 508061104), made by OpticalGauging Products Incorporated, Rochester N.Y. equipped with Smart ScopeMeasurement Software version 4.32. This procedure involves locating apeak or valley region of the sheet, focusing the video measuring systemand zeroing the Z-dimension on the measuring device. The video measuringis then moved to an adjacent valley or peak region, respectively, andthe microscope is refocused. To measure the average height differential,(i.e., Z directional depth) focus on the peak of the protruding elementof interest, and zero the Z-axis. Focus downward until the next point ofinterest (base of adjacent valley; between the two protruding elements)is in focus. Distance moved will be displayed at the bottom of thescreen in millimeters.

[0108] The display of the instrument indicates the height differencebetween this peak/valley or valley/peak pair. This measurement isrepeated at least 5 times, at random locations on the sheet, and theAverage Height Differential is the average of these measurements.

[0109] B. Peak-to-Peak Distance

[0110] The above instrument can be used to measure peak-to-peakdistance. The magnification used should be sufficient to readily measurethe distance between two adjacent peaks. To measure the Peak-to-Peakdistance, focus the scope on the top of one peak of a protrudingelement. Line up the reference point of interest, i.e. the peak of aprotruding element, with the vertical line on screen. Depending on thedirection measured to the adjacent peak, zero the X- or Y-axis. Movesample stage until the next measuring point, i.e. the peak of the nextprotruding element, lines up with the vertical line on the screen. Thedistance between the peaks of the protruding elements will be displayedat the bottom of the screen in millimeters. This measurement is repeatedat least 5 times, at random locations on the sheet, and the AveragePeak-to-Peak Distance is the average of these measurements.

[0111] A number of measurements of peak-to-peak and height differentialare taken and the average calculated. These values are used to calculatethe topography index for region two of the substrate.

[0112] C. Substrate Caliper Rebound Test Methodology:

[0113] This test is based on measuring the thickness of the finishedsubstrate before and after a pressure load has been applied andsubsequently removed. The percentage recovery of substrate thicknessafter the pressure load has been removed provided a measure of caliperrebound.

[0114] The thickness of the substrate is determined using a modifieddigital Mitutoyo Caliper gauge (Mitutoyo Digimatic Indicator, availablefrom Measure-All-Inc, Fairfield, Ohio, Catalog number 543-272 withtension spring removed), which is lowered very slowly to the surface ofthe substrate. To ensure accuracy, the substrate is supported by an 8inch by 12 inch granite base (available from Measure-All-Inc, Fairfield,Ohio, Catalog number 60812-IRS). Additionally, the digital caliper gaugeutilizes the following accessories: (1) Ono Sokki Release Cable [catalognumber AA-816], (2) 1 inch extension [catalog number 20-278-8], (3)1.596 inch diameter contact point [catalog number P-500A-1.596], (4)swivel contact point adapter [catalog number 89-050022] and (5) weightstud [catalog number 10175W]. All these component can be obtained fromMeasure-All Inc. Fairfield, Ohio. The substrate is placed under thedigital Mitutoyo Caliper gauge without any additional weights (pressureof gauge foot is under 0.038 psi) to measure initial thickness of thesubstrate. A weight of known amount is then added to bring total footpressure to 0.066 psi. The weight was left on the foot and substrate for10 minutes, in order to simulate a typical consumer usage period forfloor wiping. At the end of the ten-minute period, the additional weightis removed, and the caliper of the sheet was again measured (without anyadditional weights, nominally under 0.038 psi). Upon weight removal, the“rebound” caliper was recorded every 30 s for up to 3 minutes. Caliperrebound is calculated by dividing the substrate caliper after 3 minutesof weight removal by the initial “no-load” caliper.

[0115] D. Thickness, Basis Weight, and Density Methods

[0116] All substrate thickness, basis weight, and density calculationsare based on measurements with the substrate under a 0.038 psi load.

[0117] The thickness of the substrate is measured by utilizing the sametest instrument as described above in the “Substrate Caliper ReboundTest Methodology.” The finished substrate is placed under the digitalMitutoyo Caliper gauge without any additional weights (pressure of gaugefoot is under 0.038 psi) to measure the thickness of the substrate. Therecorded units of the thickness measurement is in millimeters.

[0118] The basis weight of the finished substrates is determined fromthe measuring the weight (in grams) of a finished substrate cut to 100mm by 100 mm. The basis weight (reported in grams/meter²) is thencalculated by the following:${{Basis}\quad {Weight}} = \frac{{Weight}\quad {of}\quad {Sample}}{{Area}\quad {of}\quad {Sample}}$

[0119] The density of the finished substrate is calculated from dividingthe basis weight (calculated from above) by the thickness of thesubstrate. The density (reported in grams/centimeter³) is calculated bythe following${Density} = \frac{{Basis}\quad {Weight}}{{Thickness}\quad \times \quad 1\text{,}000}$

What is claimed is:
 1. A nonwoven substrate suitable for use as acleaning sheet having density of no more than about 0.15 g/cm³ andcomprising at least one fibrous web, said substrate further comprisingat least one first region and at least one second region wherein said atleast one second region comprises protruding elements and is capable ofgreater geometric deformation than said at least one first region.
 2. Anonwoven substrate according to claim 1 wherein said first regions andsaid second regions are visually distinct from one another.
 3. Anonwoven substrate according to claim 1 wherein the first and secondregions are comprised of the same material composition.
 4. A nonwovensubstrate according to claim 1 wherein at least one second regioncomprises protruding rib-like elements.
 5. A nonwoven substrateaccording to claim 4 wherein said protruding elements are contiguouswith no first regions between them.
 6. A nonwoven substrate according toclaim 4 wherein said protruding elements are contiguous with no unformedregions between them.
 7. A nonwoven substrate according to claim 1wherein at least a portion of said protruding elements are capable offolding to cover an adjacent contiguous protruding elements, formingpockets suitable for collection and entrapment of soil.
 8. A nonwovensubstrate according to claim 1 wherein at least a portion of saidprotruding elements are capable of folding to cover an adjacent firstregion, forming pockets suitable for collection and entrapment of soil.9. A nonwoven substrate according to claim 1 wherein at least a portionof said protruding elements are capable of folding to cover an adjacentfirst region and adjacent protruding element, forming pockets suitablefor collection and entrapment of soil.
 10. A nonwoven substrateaccording to claim 1 wherein the first and second regions are arrangedin strips across the substrate.
 11. A nonwoven substrate according toclaim 1 wherein the first and second regions are arranged in wavesacross the substrate.
 12. A nonwoven substrate according to claim 1wherein a portion of said first regions extend in a first directionwhile the remainder of said first regions extend in a second directionwhich intersects said first direction at intervals and said firstregions form a boundary at least partially surrounding said secondregions.
 13. A nonwoven substrate according to claim 1 wherein saidsubstrate has density of no more than about 0.12 g/cm³.
 14. A nonwovensubstrate according to claim 1 wherein the substrate has caliper of noless than about 0.7 mm.
 15. A nonwoven substrate according to claim 1wherein the substrate exhibits caliper rebound of greater than about65%.
 16. A nonwoven substrate according to claim 1 wherein the substratehas basis weight of from about 10 to about 120 grams/meter².
 17. Anonwoven substrate according to claim 1 comprising at least twodifferent fiber types, the fibers differing from one another by at leastone of: (i) fiber length; (ii) fiber diameter; (iii) fiber chemistry;(iv) fiber finish; and (v) mixtures thereof.
 18. A nonwoven substrateaccording to claim 1 wherein said substrate is composed of at least onelightly bonded web.
 19. A nonwoven substrate according to claim 1wherein said substrate is composed of at least one lightly entangledweb.
 20. A nonwoven substrate according to claim 1 wherein saidsubstrate is a single fibrous web.
 21. A nonwoven substrate according toclaim 20, wherein said web is spunbond.
 22. A nonwoven substrateaccording to claim 1 wherein the substrate is a laminate of webscomprising at least one fibrous web.
 23. A nonwoven substrate accordingto claim 1 wherein the substrate is a laminate of at least a fibrous weband a reinforcing web.
 24. A nonwoven substrate according to claim 23wherein said substrate comprising at least two fibrous webs and areinforcing web, wherein said reinforcing web is sandwiched between saidfibrous webs.
 25. A nonwoven substrate according to claim 1 wherein thesubstrate is a laminate of at least a fibrous web and an extensible web.26. A nonwoven substrate according to claim 25 wherein said substratecomprising at least two fibrous webs and an extensible web, wherein saidextensible web is sandwiched between said fibrous webs.
 27. A nonwovensubstrate according to claim 1 wherein the substrate is a laminate of atleast a fibrous web and a reinforcing extensible web.
 28. A nonwovensubstrate according to claim 27 wherein said substrate comprising atleast two fibrous webs and a reinforcing extensible web, wherein saidreinforcing extensible web is sandwiched between said fibrous webs. 29.A nonwoven substrate according to claim 23 wherein said reinforcing webis composed of spunbond fibers.
 30. A nonwoven web according to any ofclaims 23 wherein the fibrous webs comprise carded staple fibers and areformed by hydroentanglement and the reinforcing web is composed ofspunbond fibers and wherein the laminate of webs are subsequentlyhydroentangled together.
 31. A cleaning sheet comprising the substrateof claim
 1. 32. A process of cleaning, preferably dry dusting, a soiledsurface by wiping a substrate according to claim 1 over said surface.33. A process of forming the substrate according to claim 1 wherein thestarting substrate is fed through a pair of corresponding rolls, atleast one of said pair of rolls comprising at least one, preferably aplurality of toothed and grooved regions about the circumference of therolls, said grooved regions forming the first regions of the substrateand said toothed regions forming the second regions of the substrate.34. A process of forming a substrate according to claim 33, wherein saidstarting substrate is fed through at least two pair of correspondingrolls.